The invention relates to a data input device for an electric data processing device, consisting of an input keyboard comprising a key field, a casing and a plug-in connection, a circuit connector comprising a connection wire, a keyboard plug and a plug connecting with the data processing device, and programmable encoder electronics.
Today such data input devices are used for example in commerce, industry, postal services or for private purposes, among other things in connection with PCs. Their respective encoder electronics coordinate the key code with the code of the corresponding data processing device. The well-known multifunctional input keyboard of the system PS/2 by IBM is provided with encoder electronics in the input keyboard and a plug-in connection. Another input keyboard with encoder electronics is shown in the leaflet "Preh Commander" 1.308 by the firm Preh.
If the computer of a data processing device is exchanged or, what happens more frequently, a keyboard is replaced, often the code of the data input device has to be adapted to the code system of the corresponding data processing device. The adaption is acheived by operations in the encoder electronics.
If the function of a key of a keyboard is to be transferred to another key, for example with respect to its application, this is achieved by operations in the encoder electronics, too, unless the data processing device renders possible such a transfer in a different way. EP 0 047 078 shows by the example of a calculator that reprogramming is possible by means of magnetic cards that can be inserted into the device. Such magnetic cards, however, require special transfer devices.
In the prior art the encoder electronics are arranged within the input keyboard. If an operation in the encoder electronics is necessary, the casing box of the keyboard has to be opened, the electronic element required, for example, for reprogramming, is to be removed out of its place in the circuit and to be treated in a programming device. Then the electronic element is reinserted into the circuit, and finally the casing box of the keyboard casing is closed again. In general, only the producer, seldom the distributor, can carry out such an operation; the operation is complicated and endangers quality.
In order to avoid the complexity of reprogramming and the endangering of quality, a plurality of different data input devices has to be produced and stored corresponding to the plurality of common data processing systems and fields of application. This is not very rational, ties up a lot of money and requires a high storing capacity.